Electrical switch-board



(No Model.)

T, J. PERRIN. ELECTRICAL SWITCH BOARD.

No. 271,914. b Patented Feb.6,1883.

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UNITED STATES THOMAS J. PERRIN, OF

PATENT OFFICE.

BROOKLYN, XE \V YORK.

ELECTRICAL SWITCH-BOARD.

SPECIFICATION forming part of Letters Patent No. 271,914, dated February 6, 1883.

I Application filed October 19, 1882. (N model.)

To all whom it may concern Be it known that I, THOMAS J. PERRIN, a citizen of the United States, and a resident of drooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in ElectricalSwitch-Boards, ct which the following is a. specification.

My invention relates to certain improvements in the construction of switch-boards,

IO such as are commonly employed at the central others of telephone and telegraph exchange systems, for placing in electrical connection .the terminals of any-two norinally-independ ent conductors or subscriber-lines, or for connecting them, either or both, with an apparatus at the central o'ifice for receiving and transmitting signals or communications.

The object of my invention is to organize a switch-board in such a manner that a complete metallic circuit embracing any two subscriber or sub stations may be established by means of one movable conductor or switchplug; to provide one point,and one only, for the insertion of the movable conductor for the purpose of connecting any two given sub-stations; and to provide means for converting the switch-board at will into a single wire or grounded circuit-board.

My invention consists in constructing a 0 switch-board with avertically-arranged series of metallic terminal conductors for each subscriber-line, the alternate terminal conductors in each series being electrically connected with each other and with the respective termi- 5 nals of the corresponding subscriber-line, and theindividualseriesthemselves being arranged in consecutive order corresponding; to the designating-numerals of the subscriber-lines, and in providing each series of terminal conductors with two series of contact-plates, one contactplate in one of the series corresponding to and connected with one set of the connected alternate terminal conductors of each ot'the numerically-succeeding series of terminal conductors 5 the contact-plates corresponding to thenumericallypreceding conductors being dispensed with. In other words, I constitute each subscriber-line a complete metallicloop and pro- Ride for each terminal thereof a terminal conductor; and, further, provide contact-plates connected with therespective terminal conduct ors in such proximity to the remaining and numerically-succeeding terminal conductors that the terminals of each loop-conductor may be placed in electrical connection with the respective terminals of any other conductor by merely inserting between the terminal conductors of one and the contact-platcot'the other a movable switch-plug provided with two insulated conducting-sections. The reason for omitting as unnecessary the contact-plates corresponding to the numerically-preceding series of terminal conductors will be apparent when it is considered that the terminals of the loop formed by any given subscriber-line may be connected with therespective terminals of any succeeding loop of the series by means of a movable cond uctor inserted between one of its own series of terminal plates and the adjacent contactplates corresponding to and connected with the said succeeding subscriber-line and also that the given terminals may be connected with the respective terminals of any preceding subscriber-line by means of a connector inserted between the said preceding terminals and the contact-plates corresponding to the given terminals.

The invention further consists in providing a series of contact-plates for normally connecting the respective terminals of each subscriberline with each other, and, through suitable apparatus for receiving and transmitting signals and communications with the earth, and in providing an additional system of contactplates similar in "their organization to those employed for connecting the terminals of any one of the subscriber-lines with the terminals of any of the other lines, whereby the circuit of any given subscriber-line may be closed through a local circuit, includingany required signal transmitting and receiving instruments.

It also consists in com bining with the switchboard suitable earth-connections, whereby one terminal of any or all of the subscriber-lines may be connected with the earth, thus combining in one general organization a metalliccircultsystem and an earth-circuit system and rendering the same interchangeable at will.

In the accompanying drawings, which illustrate my invention, Figure l is a front elevation of a switch-board embodying its essential features. Fig. 2 is a view in perspective of the coupling-pin or connector which I employ.

Referring to Fig. 1, A represents the frame IOL or board which supports the various devices which collectively constitute the switch-board.

The numerals 1 to 9, inclusive, represent a series of normally -independent subscriberlines, nine in number. The terminals of these lines are respectively connected with corre sponding series ofterminal conductors orplates of metal, (designated as a 7) (b b (6 b, &c.,) which constitute the terminals proper of the respective subscriber-lines. These series of plates are preferably arranged vertically, and in consecutivenumerical order, upon the board A, beginning at the left side and increasing numerically toward the right to the number 5, while they at the same time successively decrease in number of plates toward the right. The sixth series of terminal plates is placed directly below the filth, and the numericallysucceeding series are placed upon the lower portion of the board, increasing numerically and decreasing in number of plates toward the left, thus filling up the space left vacant by the decreasing lengths of the series of plates upon the upper portion of the board.

The individual plates of each series are electrically insulated from each other upon the face of the board; but the alternate plates are electrically united by means of conductors be-' neath or upon the back of the board. Thus all the plates designated as a are detached from each other, but are electrically united by conductor 00, as indicated in Fig. 1. In like manner the plates 1) b are insulated from the adjacent plates at a, but are electrically united by the conductor y. The same principle of organization is carried out through all the succeeding series. Thus each vertical row of terminal plates consists of two distinct series or sets of plates alternating with each other and constituting the two terminals of the looped subscriber-lines l 2 3, &c.

By placing any one of the plates to in electrical connection with any one of the plates 1) the two terminals of the corresponding subscriber-line will be placed in electrical connection with each other; or if a series of plates (1/ be connected with a plate of another subscriber-linefor instance, a and likewise the series I) with the series b it is apparent that the two loop-conductors constituting the two subscriber-lines 1 and 2 will be formed into one complete circuit. For the purpose of readily efi'ecting this result whenever desired I provide the series of terminal conductors connected with the subscriber-line 1, upon either side with contact-plates d and 0, one corresponding to and connected with each of the two sets of each of the succeeding series of terminal conductors. The contact-plates d e are numbered from 2 to 9, inclusive, there being two contact-plates for each number. The even numerals are preferably arranged upon the left of the series a b, and the uneven numerals upon the right thereof. Each contact-plate ot' the series (1- d 6%., is electrically connected by a corresponding transverse branch conductor, M, beneath the board,

with that set of terminal plates to which is (168 ignated by a corresponding numeral, and the corresponding contact-plates, c c", 830., are in like manner connected with the other set, I), (designatedbythesamenumeral.) Thusitwill be understood that the several series of con: ductors al),&c., are provided with adjacentcontact-plates for connecting them, respectively, with the respective sets of any of the remaining series at'will. In order to conveniently effect this result, I construct the board with suitable apertures between the terminal conductors and the contact-plates for the insertion of a movable conductor 0, (shown in Fig. 2,) adapted to place one conductor, a, in electrical connection with an adjacent plate, 61 and at the same time the corresponding conductor, 1), in similar connection with the corresponding plate, 0

The contact-plates upon the right of the terminal conductor a b serve also for making connections upon their opposite sides with the second series of terminal conductors,a b and another double series of contact-plates, d 0 d -6 820., corresponding with the numer|callysucceeding terminals, which are designated by the even numerals, is arranged upon the right of the series of terminal conductors a In like manner each series of terminal conductors a b, a If, a I), &c., is provided upon one side with contact plates corresponding to and transversely connected with the terminals (designated by the uneven numerals) greater than its own, and upon the other side with contact-plates of the same character (designated by the even numerals.)

Connected with each longitudinal series of conductors, and preferably arranged in two horizontal rows at the bottom of the boa-rd, are two additional contact-plates or conductors,f and g, of the same general construction as those constituting the vertical series a I). The conductorsf and g are likewise each provided with an adjacent contact-plate, It, which are organized in a manner similar to the corresponding contact-plates, d and 0, one being adjacent to each of the conductorsf and g. All the contact-plates h adjacent to one system of conductors f or g-for instance those designated as f are electrically united by a conductor, z, and in like manner the remaining contact-plates adjacent to the conductors g are united by a wire, z. The two systems of connected plates are connected with each other by a wire, 2 within which are included suitable signal transmitting and receiving devices, K and It, and a battery, 0. The loop thus formed is related is ,each of the subscriberlines in substantially the same manner as the latter are related to each other, and, as will be evident, the respective terminals of any one of the subscriber-lines maybe connected with the respective terminals of this local circuit by inserting the double switch-pin between the corresponding conductorsf and g at the bottom of the board and the adjacent contactplates.

sulated from each other by a section, also .Fig. 2, secured to a suitable handle, 0, of hard tuning-fork, and thereby rendered somewhat For the purpose of enabling any subscriber l to call the operator at the central station I provide an additional conducting-strip, N, which extendsbetween the twohorizontal rows of conductorsfand g, and is employed for normally connecting the respective terminals of each subscriber-line through a suitable receiving'in'struinent with the earth, the purpose being to receive the calls of the subscribers directly through a telephone without the use of visual signals. The strip N is therefore connected by a wire, n, with the earth at G, and suitable telephonic transmitting and receiving devices, T and T, are included in this circuit. \Nhen any line is not in use its two terminals are connected with each other and with the earth through the wire a by the insertion ofa suitable switch-plug or movableconductor between the conductors f and g, connected therewith, and the listening-strip N.

The movable conductor or connector 0 consists preferably of two metallic sections, 0 0,

rubber or other insulating material, and inof non-conducting material. The two metallic sections 0 0 are each provided with two contact-surfaces, 0 upon their opposite sides, and are preferably cut away through their central portion, as indicated at 0*, in the manner of a resilient, and hence better adapted to establish electrical connections between the various terminal conductors and their adjacentcontactplates.

The operation of a telephonic-exchange system organized in this manner is as follows: The subscriber-lines are each provided at the substations with a signal-receiving device and asuitabletelephonictransmitting device. The transmitting device which I prefer to employ is one adapted to transmit electric currents or undulations correlative with the air vibrations occasioned by the sounds which it is desired to transmit over both wires-that is, a portion over one wire and the remainder over the other wire-according to the method employed in the so-called secret telephone system, based upon the invention set forth in the patent issued to J. H. Rogers, No; 251,292, December 20, 188l.- Both terminals of all the subscriber-lines are for this purpose normally connected at the central office through the listening operators telephone T with the earth at G by means of the movable conductors (J, inserted between the plates fg and the strip N. Any individual subscriber desiring to be placed in communication with anothercalls to the operator at the central station to that effect through his transmitter. Theelectrical impulses created thereby traverse the two conductors comprising the subscriber'line, reunite at the central station, and are received in their proper order by the operator. The operator, upon thus learning, from subscriber No. 2, for instance, that be desires to be connected with subscriber No.5,

removes the coupling-pin G from its normal position between the strip N and the corresponding conductors, f and g, and inserts it between the same conductors and the adjacent contact-plates h, thereby placing the terminals of the subscriber-line 5 in connection with the terminals of the local signal-transmitting circuit By closing the circuit of the battery 0 therethrongh the signal-receiving device ,at sub-station 5 will be actuated. After calling subscriber No. 5 the operator at the central station removes the respective switch-pins G, transferring one of them to the aperture between the vertical conductors 2 and 2 and the contact-plates 5 and 5. The terminals of the two subscriber-lines Nos. 2 and 5 are now in direct electrical connection.

The manner of connecting any calling subscriber with another whose designating-numher is numerically greater than that of the calling subscriber corresponds precisely to that already described. The only difference in the method of con net-ting a calling-subscriber with another subscriber whose designating number is less than his own consists in uniting the two by employing the vertical terminal conductors of the subscriber designated by the lesser numeral, which is effected by connecting the same with the adjacent contact-plate of the subscriber designated by the greater numeral. In other words, every connection between two subscribers is made by connecting the terminals designated by the lesser numeral with the contact-plates connected with the terminal conductors designated by the greater numeral.

It will be understood from the foregoing description that for each possible combination of any two subscribers one point of connection only is provided, an orgai'iizatiou which materially reduces the size of the board and simplifies the construction of the same by canceling one'half the usual number of apertures for receiving the switchplugs or connectors.

I have described the switch-board with reference especially to the secret telephone system, wherein both wires are used for transmitting in the manner of a single conductor, the earth being employed for completing the circuit. It is evident, however, that by severing the earthconnections at the subscriber-stations and the conductor a at the central station and inserting the instruments in the loop'conductor the switch-board may be employed with equal facility for complete metallic-circuit systems, in which no connection is made with the earth. For the purpose of rendering the board applicable to the ordinary single-wire-telephoue systems, and at the same time to provide against the interruption of communication with any subscriber in the event of the breaking of one of the wires connecting him with the central station, I provide additional means for connecting either one of the terminals of any of the lines with the earth, thereby making a complete circuit through the remaining conductor.

The method of carrying out this part of my invention consists in providing at a convenient point near the series of calling contactplates h an additional conducting-plate,N, which is connected by a wire, N with the earth. The plate N is provided with two contact-plates, H H, constituting a continuation of the series h, and respectively connected therethrough with the opposite terminals ofthe local signalingcircuit 2 When it is desired to employ the board for single-wire connections, a single switch-pin or movable conductor of ordinary construction is inserted between the plate N and one or the other of the adjacent contact-plates H or H, according as it is desired to ground one terminal or the other of the local circuit; and this is determined by ascertaining with which of the plates, f or g, the subscriber-wire which it is desired to employ is connected. Thus if the wire leading to the plate f be broken and it is desired to communicate through the wire leading to the plate g, the contact-plate H should be connected with the earth, and the circuit is thus completed through the battery 0 and the instruments K and It to the contact-plates h, which in turn are placed in connection with the subscriber-wire by means of a single switch-pin inserted between the conducting-plate g and the adjacent con tact-plate h. Any particular subscriber may thus be signaled, as in'the first instance.

The plan of connecting two subscribers together by means of one wire consists in inserting a single movable connector between the particular contact-plate and the vertical terminal conductor, which are connected with the respective line-conductors and are adjacent to each other.

I have shown and described my invention as applied to a board adapted to accommodate nine subscriber-lines; but it is evident that the principle maybe extended to any desired number without departing from my invention.

I claim as my invention-- 1. The combination, substantially as hereinbefore set forth, of a series of line-wires, each constituting a complete metallic loop, a series of terminal conductors arranged in vertical rows, one row for each loop, the alternate conductors in each of which rows are electrically connected with each other and with the respective terminals of the corresponding loop, and transverse branches extending from each electrically-connectcd set of the vertically-arranged conductors, each of which branches passes in proximity to the corresponding set of vertically-arranged and alternately-connccted conductors between itself and one extreme of the series.

2. The combination, substantially as hereinbefore set forth, of a series of line-wires, each constituting a complete metallic loop, a series of terminal conductors arranged in vertical rows of systematically-decreasing lengths, one row for each loop, the successive rows of a portion of which series abut the successive rows comprised in the remainder of the series, commencing with the opposite extreme thereof,

electrical connections uniting the alternate terminal conductors in each vertical row, and transverse branches extending from each clec trically-connected set of vertically-arranged conductors, each of which branches passes in proximity to the corresponding set of all the vertically-disposed and alternately-connectcd conductors between itself and one extreme of the series.

3. The combination, substantially as hereinbefore set forth, of a series of line-wires, each constituting a complete metallic loop, a series of terminal conductors arranged in vertical rows, one row being provided for each loop, while the alternate conductors in each of said rows are electrically connected with each other and with the respective terminals of the corresponding loop, transverse branches extending from each electrically-connected set of vertically-arranged conductors, each of which branches passesin proximity to the corresponding set of all the vertically-disposed and alternatelyconnected conductors between itself and one extreme of the series, and movable connectors for electrically uniting any pair of alternating terminal conductors with the respective alternate terminal conductors of any other pair through the corresponding transverse branches at the point of proximity of the respective terminal and branch conductors.

4. The combination, substantially as hereinbefore set forth, of the series of terminal conductors a b, the conductors 00 y, the contactplates d c, and the transverse branch conductors M.

5. The combination, substantially as hereinbefore set forth, of the series of terminal conductors a b, the conductors 0c 1 the contact plates 01 e, the transverse conductors M, the contactstrip N, the conductor a, the transmitting and receiving apparatus T and T, and the conductorsfand g.

6. The combination, substantially as herein before set forth, of the series of terminal conductors a b, the conductors my, the contactplates (1 e, the transverse conductors M, the series of conductorsfg, the series of contactplates h h, the conductors z, z, and 2 battery 0, and apparatus for sending or receiving signals or communications included in the circuit of said battery.

7. The combination, substantially as hereinbefore set forth, of the series of terminal conductors a b, the conductors w 11 the contactplates (1 e, the transverse conductors M, the series of conductorsfg, the series of contactplatesh h, the battery 0, the conductors z, z, and Z2, the transmitting and receiving apparatus K and R, the plate N, and the conduct or N 8. The combination, substantially as hereinbefore set forth, of a series of subscriberlines, each consisting of a pair of conductors, a series of consecutively-nun]bered rows of alternately-connected terminal conductors, one row for each pair of conductors constituting asubscriber-line, aseries ofcontact-plates upon each side of each of said rows, the plates upon one side being designated by even, and those upon the opposite side by odd, numerals, but in all cases greater than the numeral which 3 designates the given conductor, and transverse conductors uniting each of said plates with the row ot'terminal conductors designated by the corresponding numeral. 9. The combination, substantially as hereiubefore set forth, of a series of subscriberlines, each consisting of a pair of conductors,

a series of consecutively-numbered rows of alternately-connected terminal conductors, one

row for each pair of conductors constituting a 

